ADA Depot - A Forum To Support Users of ADA Amplification Gear

Please login or register.

Login with username, password and session length
Advanced search  

News:

Lets get Technical > All Things Tube All about preamp and power amp Tubes.

Pages: 1 ... 8 9 [10] 11 12 13   Go Down

Author Topic: New Tubes Advice  (Read 115081 times)

0 Members and 1 Guest are viewing this topic.

MikeB

  • Full Member
  • ***
  • Offline Offline
  • Posts: 247
Re: New Tubes Advice
« Reply #135 on: Time Format »

Having just replaced my old tube board that was blowing up tubes I have bought a mullard short plate and put it in V1.  Surviving Boogie STR in V2. I now understand what is being said about the mullards. I have to admit that this tube is totally exposing my sloppy technique!!  :facepalm: I can clearly hear every little nuance in my style (intentional or otherwise). In the short term this will be frustrating but I'm hoping that in the long term i will be forced to sharpen up my playing.  It has only been in for a week or so,  so i can't vouch for its longevity. Fingers crossed that i get more than a month out of it.
Logged
I don't feel tardy!

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #136 on: Time Format »

Hey David, 3 in a row from different suppliers is very strange, did you tell the suppliers ? Maybe there's a bad batch which didn't get the vacuum sealed properly ?? Particularly since the other tubes don't have an issue. SC's had one in his MP1 for ages though his is a NOS so they pumped the vacuum better back then.
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

Systematic Chaos

  • Administrator
  • Hero Member
  • ******
  • Offline Offline
  • Posts: 705
  • Blood type: Becks Positive
Re: New Tubes Advice
« Reply #137 on: Time Format »

Well i had new tubes fail within a minute,so yes it can happen but 3 times is alot.Maybe the problem is the low heater voltage that destroys these?
+1

IsnĀ“t the MDRT taking care of this? (Higher and way more stable).

Also, I been using Mullard RIs (long plates) in my Triaxis since 2011 and had never one to fail. That specific rig was also transported in various rapid changing temp and rough environments (C130 Herc, C160 Transall,...)
No issues 
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #138 on: Time Format »

I think Davids MP1 is stock, but it shouldn't be blowing tubes where others work fine. Seems more like a bad batch to me, as most experience (and mine) with the Mullards is they are a very solid tube, like SC (well not quite the same  ;) ) mine get a good shaking down some country tracks very regularly (and some times my wall warts shake loose).  If there was a bad batch from the factory, many suppliers may have a few of them.
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

trader144

  • Full Member
  • ***
  • Offline Offline
  • Posts: 149
Re: New Tubes Advice
« Reply #139 on: Time Format »

Thanks all
Are you guys using mullard NOS or reissues? I was using reissue long plates in a very stable temp environment.

Maybe they can't handle the shredding  ;)

The vendors all warrantied them and took them back or replaced it.
Not sure if this matters but my battery just died yesterday after 35? years of faithful service.

I am going to try the noise and battery mod (on the way from marshalljmp) with the groove tubes and see what i get.

If not good enough I will probably go with the mdrt (anyone want to get rid if an uninstalled kit?)

Logged
Guitars: Malmsteen strat, Fender '62 reissue
Rig: Avid 11 Rack -> ADA MP-1 (stock) ->  ADA Microtube 100 -> ADA split stack

trader144

  • Full Member
  • ***
  • Offline Offline
  • Posts: 149
Re: New Tubes Advice
« Reply #140 on: Time Format »

FWIW, I have tested the tubes SC recommended: TAD 12AX7A-C RT001

I agree with SC, they sound very, very close to the original MP-1 tubes. Hope they last as long.

Logged
Guitars: Malmsteen strat, Fender '62 reissue
Rig: Avid 11 Rack -> ADA MP-1 (stock) ->  ADA Microtube 100 -> ADA split stack

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #141 on: Time Format »

Hi David, I've got 4 x long plate reissues, 2 in each MP2, they haven't miss a peep/beat and they've been in a few years now and get regular use. Also they go up and down to the coast from Canberra 700 metres down to sea level and back, and also get a nice bump down a dirt track in the back of a ute (pick up in US ?)
Unfortunately no new tubes (that I'm aware of) will last as long as the old Chinese bottles, they were pumped much longer back then, better vacuum = longer life. In this throw away age, they don't have much incentive to make them last more than maybe a year or 2. That said, these Russian tubes are still going strong and still sound great. I still think it was a bad batch from the factory.
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

MikeB

  • Full Member
  • ***
  • Offline Offline
  • Posts: 247
Re: New Tubes Advice
« Reply #142 on: Time Format »

Well now I'm all concerned that there's a bad batch of mullards around. Trader, were yours the long or short plates?
Logged
I don't feel tardy!

trader144

  • Full Member
  • ***
  • Offline Offline
  • Posts: 149
Re: New Tubes Advice
« Reply #143 on: Time Format »

Long plates.
My MP-1 is all stock and I will be doing the noise/battery mod soon.

I am really thinking about MarshallJMP's comment about the transformer....it is 34 years old.

David
Logged
Guitars: Malmsteen strat, Fender '62 reissue
Rig: Avid 11 Rack -> ADA MP-1 (stock) ->  ADA Microtube 100 -> ADA split stack

MikeB

  • Full Member
  • ***
  • Offline Offline
  • Posts: 247
Re: New Tubes Advice
« Reply #144 on: Time Format »

I've gone with a short plate. Up until last month, mine was completely stock.  Now has a new MJMP mod shop tube board and noise mod.  Now that there is this heater voltage issue, i will definitely go the MDRT  transformer mod....just as soon as he gets some more in stock.  I also worry about the age of this thing.  I'm pretty sure i dont own anything else that old, and if i did i probably wouldn' t be expecting it to still be performing perfectly every day.
Logged
I don't feel tardy!

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #145 on: Time Format »

They are amazing preamps, and as you know MikeB, that MP1 has done allot of gigs, as has my live MP2.
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

trader144

  • Full Member
  • ***
  • Offline Offline
  • Posts: 149
Re: New Tubes Advice
« Reply #146 on: Time Format »

Tube question:

When I listen to artists and the MP-1, it seems that there is some sort of a distortion curve and a compression curve in a tube.
To get the right "sound" you need to drive your tubes to an intersection of these two curves that you prefer. Further to maximize the sound quality your tube choice needs to operate well at this intersection.

For me, I want this from my mp-1 and microtube/gcs-3 at bedroom levels:
1. OD2 to have full driven tube compression with a little sting at all times (like a clean setting on a tube amp that is driven too hard to be clean)
2. Kick in more distortion with OD1.
3. Mullard sound

I can get 2 and 3, but #1 escapes me. I have a mullard 12AT7 on the way to try because the 12ax7 and 12at7 combo sounded great on the bias software.

Anyone been able to do #1?

David


Logged
Guitars: Malmsteen strat, Fender '62 reissue
Rig: Avid 11 Rack -> ADA MP-1 (stock) ->  ADA Microtube 100 -> ADA split stack

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #147 on: Time Format »

Hey David
Interesting question. First is a bit of how you use the word compression, tubes have a very wide dynamic range and, as such, don't compress in the same sense that compressors do (i.e. reduce dynamic range of a signal).  However, clipping a tube (as we do to make distortion does make the softer parts of the signal louder comparatively, so from a guitarist perspective they dynamic range is flattened (not that tubes can't be used in a compressor circuit, the better ones do, but not to compress (in a pure audio sense))). So I'm not sure about a compression curve as such.  The distortion is caused by clipping, feeding in more than it's designed to take (the design of these tubes comes from making them as clean as possible), fortuitously for us guitar heads, tubes clip giving off even harmonics which sound nice (as we all know and use). So any distortion curve will relate to how a tube reacts to being over driven into clipping.
Re 12AT7 (there are some other posts relating to this model and how it reacts after a 12AX7, and also used as a phase splitter in a tube power amp).  12AT7s are bright (a bit harsh), less gain and higher current than 12AX7.  Better choice may be 12AY7, more rounded than 12AT7 but similarly less gain than 12AX7.
Personally, I'm really liking the 2 Mullard 12AX7 long plates in my MP2s.
But let us know how you go with the 12AT7  :thumb-up:
Cheers R
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few

trader144

  • Full Member
  • ***
  • Offline Offline
  • Posts: 149
Re: New Tubes Advice
« Reply #148 on: Time Format »

Thanks I was sure I was describing it wrong
There is something that limits the sound when fully driven and for the more classic tubes you can hear some of the frequencies seem to hit a wall and the sound seems to compress. Maybe this is the rounding but I got an excellent round sound with a mullard at low levels.

At this wall the tube gets overdriven, the frequencies barely push past and the distortion is more of a stingy unplanned type, not fuzzy or digital. It's Like the tube is sweating.

I am getting too much digital and not enough cleaner round from my mp-1.

Is getting to here simply trying 12ay/Au/5751?

« Last Edit: Time Format by trader144 »
Logged
Guitars: Malmsteen strat, Fender '62 reissue
Rig: Avid 11 Rack -> ADA MP-1 (stock) ->  ADA Microtube 100 -> ADA split stack

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5996
Re: New Tubes Advice
« Reply #149 on: Time Format »

Hey David, advice to me (audio file tube head Friend) is stay away from 12AU7s (they have their place but not for this), ATs and AY7s will work and may do what you want ?? The great thing with the Mullards (long plates) is they are so open (good clean linear gain), no fuzz or other crap (well that's my experience with them in MP2).
Whats the rest of your patch set up ? What/how are you combining EXs ?
Logged
Studio Rig: Stuff; Live Rig: More Stuff; Guitars: A few
Pages: 1 ... 8 9 [10] 11 12 13   Go Up